Composite pane comprising sun shading coating

Abstract

To provide a further improved composite pane having a sun-shading function.SOLUTION: A composite pane 100 includes an outer pane 1, an inner pane 2, and a thermoplastic intermediate layer 3, and has at least one sun-shading coating 4 between the outer pane 1 and the inner pane 2. The sun-shading coating 4 comprises, starting from the outer pane 1 toward the inner pane 2, a layer sequence "a first dielectric module (M1) / a first silver layer (Ag1) / a second dielectric module (M2) / a second silver layer (Ag2) / a third dielectric module (M3) / a third silver layer (Ag3) / a fourth dielectric module (M4)". The silver layers (Ag1, Ag2, Ag3) have, relative to one another, geometrical layer thickness of 0.4<Ag1 / Ag3<1.7, and Ag3 or Ag2 is the thickest silver layer. The dielectric modules (M1, M2, M3, M4) have, relative to one another, an optical layer thickness of M2 / M1≥1.9, M2 / M3≥0.8, and M2 / M4≥1.6.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a composite pane having an improved solar shielding coating and uses thereof. [Background technology]

[0002] DE 19927683 A1 discloses a universal composite pane comprising at least two glass panes joined together by a transparent interlayer and further comprising a solar shading layer which substantially reflects solar radiation, in particular infrared radiation outside the visible spectrum of solar radiation, in particular infrared radiation, where the composite glass pane is further provided on its surface facing the interior space with another transparent coating (also called low-E layer) which substantially reflects thermal radiation and is spatially separated from the solar shading layer.

[0003] WO 2013 / 127563 discloses another generic composite pane with a solar shielding layer between glass panes and a low-E coating on its inner surface, the thermal radiation reflective coating being based on niobium, tantalum, molybdenum or zirconium.

[0004] WO 2019 / 110172 discloses a composite glass pane comprising an outer pane having an outer surface and an inner surface, an inner pane having an outer surface and an inner surface, and a thermoplastic interlayer bonding the inner surface of the outer pane to the outer surface of the inner pane, wherein the composite pane has at least one solar radiation shielding coating between the outer pane and the inner pane that substantially reflects or absorbs light outside the visible spectrum of solar radiation, in particular infrared radiation. Also, wherein the composite glass pane has a thermal radiation reflective coating on the inner surface of the inner pane. The composite pane has a transmittance index A of 0.02 to 0.08, the transmittance index A being determined as follows:

number

[0005] TL is the light transmittance level and TE is the energy transmittance, each measured according to ISO 9050. TL VSG refers to the light transmittance through the entire composite pane, while TL LOWE represents only the light transmission through the inner pane in conjunction with the infrared-reflecting low-E glass coating. The TL value can be appropriately adjusted by selecting the tinting of the components of the composite pane, i.e. the inner pane, the outer pane and the interlayer. The TE value is likewise determined by the selection of the tinting of the components of the composite pane and further by the properties of the solar-blocking coating and the thermal radiation-reflecting coating. With such composite panes, low TTS values ​​of less than 50% could be achieved in combination with low light transmission of 1-12%.

[0006] German Utility Model No. 202020100793 discloses a vehicle roof panel with an interference coating for preventing reflections of a display device. The interference coating comprises a plurality of conductive silver layers, with dielectric layer structures located between, above and below the silver layers. Each of the dielectric layer structures comprises n optically low refractive index layers having a refractive index less than 1.8, and (n+1) optically high refractive index layers, where n is an integer equal to or greater than 1.

[0007] WO 2020 / 094423 describes a projection device for a head-up display (HUD), which includes a composite pane having a conductive coating and a projector, where the conductive coating includes at least three conductive layers, where the sum of the thicknesses of all the conductive layers is at most 30 nm, and where the conductive layers have a thickness of 5 nm to 10 nm. Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to provide a further improved composite pane with solar shading function, where the energy, thermal and optical properties of the composite pane should be further improved and a reflected color that is visually appealing and as independent as possible from the viewing angle should be achieved.

[0009] This problem is solved according to the invention by a composite pane according to independent claim 1. Advantageous embodiments of the invention are evident from the dependent claims. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The composite pane of the present invention includes an outer pane having an outer surface (side I) and an inner surface (side II), an inner pane having an outer surface (side III) and an inner surface (side IV), and a thermoplastic intermediate layer bonding the inner surface of the outer pane to the outer surface of the inner pane; wherein the composite pane has at least one solar shading coating between the outer pane and the inner pane, which substantially reflects or absorbs light outside the visible spectrum of solar radiation, in particular infrared radiation; wherein the solar shielding coating comprises, viewed in the direction of the outer pane, the following layer sequence: a first dielectric module (M1), - a first silver layer (Ag1), - a second dielectric module (M2), - a second silver layer (Ag2), - a third dielectric module (M3), - the third silver layer (Ag3), -Fourth dielectric module (M4)

[0011] The silver layers (Ag1, Ag2, Ag3) of the solar radiation shielding coating according to the present invention have a geometric layer thickness of 0.4 < Ag1 / Ag3 < 1.7 with respect to each other. Here, Ag3 or Ag2 is the thickest silver layer, and here, the thicknesses of the silver layer Ag3 and the silver layer Ag2 can be made the same. The dielectric modules (M1, M2, M3, M4) have an optical layer thickness of M2 / M1 ≧ 1.9, M2 / M3 ≧ 0.8, and M2 / M4 ≧ 1.6 with respect to each other. All dielectric layers of the dielectric modules (M1, M2, M3, M4) have a refractive index greater than 1.8.

[0012] The structure of the layer arrangement of the solar radiation shielding coating according to the present invention is viewed starting from the direction of the outer pane. This means that the first dielectric module is the layer closest to the inner surface (second surface) of the outer pane of the solar radiation shielding coating, followed in this order by the first silver layer (Ag1), the second dielectric module (M2), the second silver layer (Ag2), the third dielectric module (M3), the third silver layer (Ag3), and the fourth dielectric module (M4). Thus, the fourth dielectric module is the layer of the solar radiation shielding coating that is farthest from the inner surface of the outer pane and closest to the outer surface (third surface) of the inner pane. The silver layers are, in each case, arranged between the dielectric modules, i.e., between the dielectric layers or layer arrangements. The solar radiation shielding coating is arranged between the inner surface (second surface) of the outer pane and the outer surface (third surface) of the inner pane and can, for example, be applied to one of the surfaces of the pane or integrated into a thermoplastic intermediate layer.

[0013] In other words, according to the invention, the layer thickness of the first silver layer (Ag1) of the solar protection coating is provided to be smaller than the respective layer thickness of one or both of the two other silver layers Ag2 and Ag3 that follow it. These silver layers are arranged above the first silver layer in the layer sequence of the solar protection coating and are therefore arranged further from the outer pane. At least two of the layer thicknesses of the silver layers Ag1, Ag2 and Ag3 are therefore different from each other. In this context, "different from each other" means that the layer thicknesses of at least two of the three silver layers are different from each other, preferably by at least 5%, particularly preferably by at least 10%, in particular by at least 15%. Furthermore, the layer thickness of the second dielectric module M2 is provided to be greater than the layer thicknesses of the other dielectric modules M1 and M4 in each case. The second dielectric module M2 or the third dielectric module M3 is the module with the largest layer thickness, and it is also possible that both modules M2 and M3 have the same layer thickness.

[0014] Surprisingly, it has been shown that such composite glass panes according to the invention have significantly improved energy properties compared to known composite glass panes with solar shading coatings and at the same time have good optical and aesthetic properties; in particular, undesirable tints in the reflection of the composite pane can be minimized or even avoided. In addition to a visually appealing reflected color per se, a minimal angle-dependent change in the reflected color is also important for high customer satisfaction. The composite panes according to the invention only show a slight angle-dependence of the reflected color.

[0015] A composite pane comprises an outer pane and an inner pane, bonded together via a thermoplastic interlayer. The composite pane is intended to separate the interior from the exterior environment in a window opening, in particular in a vehicle window opening. In the context of the present invention, "inner pane" refers to the pane of the composite pane facing the interior, in particular the interior of a vehicle. "Outer pane" refers to the pane facing the exterior environment.

[0016] The composite pane has an upper edge and a lower edge and two side edges extending therebetween. The term "upper edge" refers to the edge intended to face upwards in the installed position. The term "lower edge" refers to the edge intended to face downwards in the installed position. In the case of a windshield, the upper edge is also called the "roof edge" and the lower edge is called the "engine edge". When the composite pane is used as a roof panel of an automobile, the two side edges extend substantially parallel to each other, respectively, above the side door of the vehicle. Thus, the upper or lower edge of the composite pane faces the windshield, and the remaining upper or lower edge is directed towards the rear window.

[0017] The outer pane and the inner pane in each case have an outer side surface and an inner side surface and a peripheral side edge extending therebetween. In the context of the present invention, the "outer side surface" refers to the main surface intended to face the exterior environment in the installed position. In the context of the present invention, the "inner side surface" refers to the main surface intended to face the interior in the installed position. The inner side surface of the outer pane and the outer side surface of the inner pane face each other and are joined to each other by a thermoplastic intermediate layer.

[0018] The solar shading coating of the composite pane according to the invention is preferably applied to one of the two pane surfaces facing the intermediate layer, i.e. the inner surface of the outer pane or the outer surface of the inner pane. Alternatively, the solar shading coating can also be arranged in the thermoplastic intermediate layer, for example on a carrier film arranged between two thermoplastic bonding films. The solar shading coating is preferably provided as an IR-reflective coating. In particular, the coating is applied to the entire surface of the pane, except for the peripheral area and optionally local areas. These areas are intended to ensure the transmission of electromagnetic radiation through the composite pane, as a communication, sensor or camera window, and therefore are free of coating. The non-coated peripheral area has a width of, for example, up to 20 cm. This ensures that the coating is protected from corrosion and damage in the interior of the composite pane by preventing it from coming into direct contact with the surrounding atmosphere.

[0019] When the composite pane is a windshield, the solar shading coating must be implemented as a transparent coating. A coating is considered to be a "transparent coating" when it has an average transmission of at least 70%, preferably at least 75%, in the visible spectral range, i.e., it does not substantially restrict vision through the pane.

[0020] Preferably, at least 80% of the pane surface is provided with a coating according to the invention.

[0021] When a first layer is placed above a second layer, this means in the context of the present invention that the first layer is placed further from the outer pane than the second layer. When a first layer is placed below a second, this means in the context of the present invention that the second layer is placed further from the outer pane than the first layer.

[0022] When the layer is based on a material, it consists largely of, in particular essentially of, this material in addition to any impurities or dopants.

[0023] A solar shading coating is a stack of layers or layer arrangements, in particular made up of thin layers, and comprises a number of silver layers. Each silver layer is in each case arranged between two dielectric layers or layer arrangements. These dielectric layers or layer arrangements are called dielectric modules. The term "dielectric module" therefore means a dielectric layer that can be formed from a single ply, i.e. a single dielectric layer, or from several plies of dielectric layers. The coating is therefore a stack of thin layers with n silver layers and (n+1) dielectric layers or layer arrangements, where n is a natural number and the silver layers and the dielectric layers or layer arrangements follow one another on the lower dielectric layer or layer arrangement.

[0024] The solar shading coating is a stack of thin layers, i.e. a layer sequence of thin individual layers, and preferably comprises at least four dielectric modules (M1, M2, M3 and M4), i.e. at least four dielectric layers. Each functional silver layer is arranged between two dielectric layers or layer sequences. The functional layers or layer sequences and the dielectric layers are arranged as follows: at least one dielectric layer is arranged in each case between two adjacent functional silver layers, between which no other functional silver layer is arranged, and at least one other dielectric layer is arranged above the top functional layer; and at least one other dielectric layer is arranged below the bottom functional layer.

[0025] The solar shading coating according to the invention has at least three silver layers, so that said natural number n is at least 3. The coating comprises at least the following layers or layer sequences, which are arranged in the given order starting from the outer pane towards the inner pane: a first dielectric layer or layer arrangement as module M1, - the first silver layer Ag1, - a second dielectric layer or layer arrangement as module M2, - The second silver layer Ag2, - The third dielectric layer or layer sequence as module M3, - The third silver layer Ag3, and - The fourth dielectric layer or layer sequence as module M4.

[0026] The coating according to the invention can include a further silver layer and a dielectric module disposed on the fourth dielectric module M4 (n > 3). However, in a particularly preferred embodiment, the natural number is precisely 3. In principle, a more complex layer structure is not necessary to obtain the essential specifications of the coating. However, in addition to the silver layer, other metal-containing layers can be present, which do not contribute much to the solar radiation shielding properties of the coating but serve another purpose. This particularly applies to metal blocking layers having a geometric thickness of less than 1 nm. These metal blocking layers are preferably disposed between the silver layer and the dielectric module.

[0027] The silver layer gives the solar radiation shielding coating a basic IR reflection effect. In this context, the term "silver layer" refers to a layer formed based on silver. The silver layer is based on silver. The silver layer preferably contains at least 90% by mass of silver, particularly preferably at least 99% by mass of silver, and most particularly preferably at least 99.9% by mass of silver. The silver layer can have dopants such as palladium, gold, copper, or aluminum.

[0028] In a preferred embodiment of the solar radiation shielding coating according to the invention, the first silver layer Ag1 and the third silver layer Ag3 have a geometric layer thickness of 0.6 < Ag1 / Ag3 < 1.7 with respect to each other, while the second silver layer Ag2 is the thickest silver layer. The dielectric modules M1, M2, M3, and M4 have an optical layer thickness with respect to each other of M2 / M1 ≧ 2, M2 / M3 > 1, and M2 / M4 ≧ 2, and the second dielectric module M2 is the dielectric module with the thickest layer thickness. This embodiment has proven to be particularly advantageous in that the angular-dependent change in the reflection color of the composite paint is further improved.

[0029] The optical thickness is the product of the geometrical thickness and the refractive index (at 550 nm). The optical thickness of the layer sequence is calculated as the sum of the optical thicknesses of the individual layers.

[0030] In another preferred embodiment of the solar radiation shielding coating according to the invention, the third silver layer is the silver layer having the largest layer thickness, and the first silver layer Ag1, the second silver layer Ag2, and the third silver layer Ag3 have geometrical layer thicknesses such that 0.4 < Ag1 / Ag3 < 0.9 and 0.5 < Ag2 / Ag3 < 1.0 with respect to each other. In this case, the first dielectric module M1, the second dielectric module M2, the third dielectric module M3, and the fourth dielectric module M4 have optical layer thicknesses such that M2 / M1 ≧ 1.9, M2 / M3 ≧ 0.8, and M2 / M4 ≧ 1.6 with respect to each other. A composite pane provided with a solar radiation shielding coating having this configuration exhibits further improved energy reflection.

[0031] According to the invention, all dielectric layers have a refractive index greater than 1.8, preferably greater than 1.9. In other words, all dielectric layers or layer sequences of the dielectric module are formed only by dielectric layers having a refractive index greater than 1.8. In this way, good results are obtained. The dielectric layer can be based on, for example, silicon nitride, mixed silicon metal nitride (e.g., silicon-zirconium nitride (SiZrN), mixed silicon-aluminum nitride, mixed silicon-hafnium nitride, or mixed silicon-titanium nitride), aluminum nitride (AlN), tin oxide (SnO), manganese oxide (MnO), tungsten oxide (WO 3 )), niobium oxide (Nb 2 O 5 ), bismuth oxide (Bi 2 O 3 ), titanium dioxide (TiO 2 ), zinc oxide (ZnO), or mixed tin zinc oxide (SnZnO).

[0032] In the context of the present invention, the refractive index is in principle stated with respect to a wavelength of 550 nm. The refractive index can be determined, for example, by ellipsometry. Ellipsometers are commercially available, for example, from Sentech. The refractive index of a dielectric layer is preferably determined by first depositing it as a monolayer on a substrate and then measuring the refractive index by ellipsometry. To determine the refractive index of a dielectric layer sequence, the layers of the layer sequence are in each case deposited alone as a monolayer on a substrate and then the refractive index is determined by ellipsometry. According to the present invention, a refractive index of at least 1.8 must be obtained for each of these individual layers. Dielectric layers with a refractive index of at least 1.8 and methods for their deposition are known to those skilled in the art of thin films. Preferably, physical vapor deposition methods are used, in particular magnetron sputtering.

[0033] The materials mentioned herein can be deposited stoichiometrically, substoichiometrically or superstoichiometrically. The materials can have dopants, in particular aluminum, boron, zirconium or titanium. The dopants can give the essentially dielectric materials a certain electrical conductivity. Nevertheless, the skilled person will identify them as dielectric layers by function, as is customary in the field of thin layers. The materials of the dielectric layers are preferably 10 -4 The material of the silver layer preferably has an electrical conductivity (the inverse of the resistivity) of less than 10 4 It has electrical conductivity greater than S / m.

[0034] Preferably, the first dielectric module, the second dielectric module, the third dielectric module and / or the fourth dielectric module comprise a dielectric layer that functions as an anti-reflection layer. In an advantageous embodiment, each dielectric module comprises a dielectric layer as an anti-reflection layer. The anti-reflection layer reduces the reflection of visible light and thus increases the transparency of the coated pane. The anti-reflection layer can be, for example, silicon nitride (Si 3 N 4 ), silicon oxide (SiO 2), silicon oxynitride, mixed silicon metal nitrides such as silicon zirconium nitride (SiZrN), aluminum nitride (AlN) or tin oxide (SnO). Furthermore, the antireflective layer can have a dopant. The antireflective layer preferably has a geometric thickness of 5 nm to 100 nm, particularly preferably 10 nm to 60 nm. Silicon nitride is particularly preferred as an antireflective layer since it has a high refractive index compared to oxides, so that the required thickness of the silicon nitride layer is relatively small. Furthermore, good color properties of the coating are obtained.

[0035] In an advantageous embodiment, the one or more dielectric modules have a first matching layer, preferably at least each dielectric module arranged under the silver layer. The first matching layer is preferably arranged on the anti-reflection layer. The first matching layer is preferably arranged directly under the first silver layer, in direct contact with the respective silver layer. This is particularly advantageous with respect to the crystallinity of the silver layer. In an advantageous embodiment, the one or more dielectric modules have a second matching layer, preferably each dielectric module arranged on the silver layer. The second matching layer is preferably arranged under the anti-reflection layer.

[0036] The first and / or second matching layer preferably comprises zinc oxide ZnO. The first and / or second matching layer also preferably comprises a dopant. The first and / or second matching layer may for example comprise aluminum doped zinc oxide (ZnO:Al). The zinc oxide is preferably deposited substoichiometrically with respect to oxygen, thereby avoiding the reaction of excess oxygen with the silver-containing layer. The geometric layer thickness of the first and second matching layers is preferably 5 nm to 20 nm, particularly preferably 8 nm to 20 nm. Zinc oxide has proven to be a preferred material for the matching layer due to its good smoothing properties, by means of which a high electrical conductivity of the adjacent silver layer can be advantageously obtained.

[0037] In an advantageous embodiment, the dielectric module or modules have at least one dielectric layer as a smoothing layer, preferably each dielectric module arranged between two silver layers has at least one dielectric layer as a smoothing layer, particularly preferably the lowermost first dielectric module also has at least one dielectric layer as a smoothing layer. The at least one smoothing layer is arranged below the first matching layer, preferably between the antireflection layer and the first matching layer, if such a first matching layer is present. The smoothing layer is particularly preferably in direct contact with the first matching layer. The smoothing layer has the effect of optimizing the surface for the silver layer then applied on top, in particular a smoothing effect. A silver layer deposited on a smoother surface has a relatively high transmittance and at the same time a relatively low sheet resistance. The geometric layer thickness of the smoothing layer is preferably 5 nm to 20 nm, particularly preferably 5 nm to 12 nm. The smoothing layer preferably has a refractive index of less than 2.2.

[0038] The smoothing layer comprises at least one amorphous oxide. The oxide may be amorphous or partially amorphous (and therefore partially crystalline), but not completely crystallized. A non-crystalline smoothing layer has a low roughness and therefore forms an advantageously smooth surface for the layer applied on top of the smoothing layer. The non-crystalline smoothing layer further leads to an improved surface structure of the layer deposited directly on top of the smoothing layer, preferably this deposited layer being the first matching layer. The smoothing layer may comprise, for example, at least one oxide of one or more of the elements tin, silicon, titanium, zirconium, hafnium, zinc, gallium and indium. The smoothing layer preferably comprises an amorphous composite oxide. Most particularly preferably, the smoothing layer comprises mixed tin-zinc oxide (ZnSnO). The mixed oxide may comprise a dopant. The smoothing layer may comprise, for example, antimony-doped mixed tin-zinc oxide. The mixed oxide preferably has a substoichiometric oxygen content.

[0039] In an advantageous embodiment, the solar-shading coating comprises one or more blocking layers. Preferably, at least one blocking layer is associated with at least one silver layer, particularly preferably with each silver layer. The blocking layer is in direct contact with the silver layer and is arranged directly above or directly below the silver layer. That is to say, no other layers are arranged between the silver layer and the associated blocking layer. The blocking layer can also be arranged in each case directly above and directly below the silver layer. The blocking layer preferably comprises niobium, titanium, nickel, chromium and / or alloys thereof, particularly preferably nickel-chromium alloys. The geometric layer thickness of the blocking layer is preferably 0.1 nm to 1.5 nm, particularly preferably 0.1 nm to 1.0 nm. The blocking layer located directly below the silver layer serves in particular to stabilize the silver layer during temperature treatment and improves the optical quality of the solar-shading coating. The blocking layer immediately above the silver layer prevents the delicate silver layer from contacting an oxidizing reactive atmosphere during deposition of the next layer by reactive cathode sputtering, for example during deposition of a second matching layer.

[0040] If the layer is based on a material, it consists mostly of this material, in addition to impurities or dopants. If a first layer is placed on top of a second layer, this means in the context of the present invention that the first layer is placed further away from the substrate to which the coating is applied than the second layer. If a first layer is placed below a second layer, this means in the context of the present invention that the second layer is placed further away from the substrate than the first layer. If a first layer is placed above or below a second layer, this does not necessarily mean in the context of the present invention that the first and second layers are located in direct contact with each other. Unless expressly excluded, one or more other layers may be placed between the first and second layers.

[0041] In an advantageous embodiment, a dielectric module is arranged, which comprises, in each case between two adjacent silver layers, the following dielectric layer sequence:

[0042] - antireflection layers based on silicon nitride, mixed silicon-metal nitrides such as silicon nitride-zirconium nitride, aluminium nitride and / or tin oxide:

[0043] smoothing layers based on oxides of one or more of the elements tin, silicon, titanium, zirconium, hafnium, zinc, gallium and indium:

[0044] a first matching layer and a second matching layer based on zinc oxide; and -Optionally, a blocking layer based on niobium, titanium, nickel, chromium, and / or alloys thereof. No particular order of layers is required. Anti-reflection and matching layers based on the preferred materials listed above are preferably placed below the bottom silver layer and above the top silver layer.

[0045] According to the invention, the dielectric module preferably has a geometric thickness in each case between 10 nm and 100 nm, particularly preferably between 20 nm and 90 nm, for example between 70 nm and 85 nm. The optical thickness of the module is obtained by multiplying the geometric thickness of the dielectric module by the refractive index of each layer. The optical thickness of the dielectric module is between 40 nm and 240 nm, preferably between 50 nm and 200 nm.

[0046] The geometric thickness of each functional silver layer of the solar-shading coating is preferably 5 nm to 25 nm, particularly preferably 8 nm to 20 nm. The total geometric layer thickness of all functional silver layers of the solar-shading coating is preferably 20 nm to 80 nm, particularly preferably 30 nm to 60 nm. In these ranges for the thickness of the functional layers and the total thickness of all functional silver layers, particularly good results are obtained in terms of solar-shading function and transparency.

[0047] The solar shading coating according to the invention has IR reflecting properties so that it acts as a solar shading coating that reduces heating inside the vehicle by reflecting thermal radiation. The TTS value of the coated composite pane is preferably less than 50%, particularly preferably less than 45%. The TTS value refers to the total solar energy transmitted, measured according to ISO 13837. It is a measure of thermal comfort. The coating can also be used as a heating coating when it is electrically contacted so that an electric current flows through it, and the coating can be heated.

[0048] The outer and inner panes are preferably made of glass, in particular soda-lime glass, which is common for window panes. However, the panes may in principle also be made of other types of glass (e.g. borosilicate glass, quartz glass, aluminosilicate glass, etc.) or transparent plastics (e.g. polymethylmethacrylate or polycarbonate). The thickness of the outer and inner panes may vary over a wide range. Preferably, panes are used having a thickness in the range of 0.8 mm to 5 mm, preferably 1.4 mm to 2.9 mm, for example standard thicknesses of 1.6 mm or 2.1 mm.

[0049] The outer pane, inner pane, and thermoplastic interlayer may be transparent and colorless, but may also be tinted or colored. The coloring of the outer pane, inner pane, and thermoplastic interlayer is selected depending on the desired application of the composite pane. When the composite pane is used as a windshield, high transmission is desired in the visible range of the light spectrum, and dark tinting of the components is not used. In one embodiment as an automobile windshield, the total transmission through the composite glass is greater than 70%, based on Illuminant A. The term "total transmission" is based on the process for testing the light transmission of automobile windows specified by ECE-R 43, Annex 3, §9.1. The outer pane and inner pane may be unprestressed, partially prestressed, or prestressed, independently of each other. If at least one of the panes is prestressed, this may be thermal or chemical prestressing.

[0050] In a preferred embodiment, the composite pane is intended as a roof panel for an automobile, where at least the thermoplastic interlayer and the inner pane are tinted, preferably dark tinted, in particular grey tinted.

[0051] Suitable glass panes include those from Saint-Gobain known under the trade names Planiclear® and Planilux® (in each case clear glass), VG10, VG20, VG40 or TSANx, TSA3+, TSA4+, the glasses of the VG series being grey-coloured glasses and the glasses of the TSA series being green-coloured glasses. To further improve the transparency TL of the composite pane in the visible light range, glass panes with particularly high transparency may also be used.

[0052] The composite pane is preferably curved in one or more spatial directions, as is customary for automobile panes, with typical radii of curvature in the range of about 10 cm to 40 m, although the composite pane can also be flat, for example when intended as a pane for a bus, train, or tractor.

[0053] The inner surface of the outer pane and the outer surface of the inner pane face each other and are bonded to each other by a thermoplastic intermediate layer. The thermoplastic intermediate layer is formed by one or more thermoplastic films. Here, in the resulting composite pane, the individual films in the resulting intermediate layer may no longer be distinguishable from each other. The thermoplastic film preferably contains polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyurethane (PU), and / or mixtures thereof and / or copolymers thereof, particularly preferably polyvinyl butyral. The film is preferably based on the above-mentioned materials, but may contain other components, such as plasticizers, colorants, IR or UV absorbers.

[0054] The thermoplastic interlayer contains at least one thermoplastic polymer, preferably ethylene vinyl acetate (EVA), polyvinyl butyral (PVB) or polyurethane (PU), or mixtures or copolymers or derivatives thereof, particularly preferably PVB. The thickness of the interlayer is preferably 0.2 mm to 2 mm, particularly preferably 0.3 mm to 1 mm. The individual polymer films of the interlayer, in particular the PVB films, preferably have a thickness of about 0.2 mm to 1 mm, for example 0.38 mm, 0.76 mm or 0.81 mm. Other properties of the composite glass pane can be influenced by the thickness of the film. For example, a thicker PVB film improves the soundproofing, increases the penetration resistance of the composite glass pane, especially when it contains an acoustically active core, and also increases the protection against ultraviolet rays (UV protection).

[0055] According to the invention, the solar-shading coating is arranged between the outer pane and the inner pane. In a preferred embodiment, the solar-shading coating is applied to the inner surface (side II) of the outer pane. In this way, the solar-shading coating is protected from the effects of weathering in the laminate of the composite pane. It is advantageous, particularly with regard to a good solar-shading effect, to arrange the solar-shading coating as far outward as possible, i.e. as close as possible to the outer surface of the outer pane. This is further optimized by using a transparent, untinted outer pane.

[0056] In another possible embodiment, the solar-shading coating is embedded in the thermoplastic interlayer. The solar-shading coating can be applied on top of a thermoplastic film. In a preferred embodiment, the solar-shading coating is applied to a carrier film that is arranged in the manufacture of the composite pane, for example between two thermoplastic films that serve to form an interlayer. The integration of the solar-shading coating via the carrier film is advantageous with regard to simple prefabrication and the provision of a carrier film with a solar-shading coating. The film of the thermoplastic interlayer, arranged between the solar-shading coating and the outer pane, is preferably transparent and colorless. The thermoplastic interlayer of the composite pane comprises a carrier film thereon, i.e. on the surface facing the outer pane, with a solar-shading coating. The carrier film preferably comprises or is made of polyethylene terephthalate (PET) and has a thickness of 20 μm to 100 μm, for example approximately 50 μm. However, the carrier film may also be made of other suitable plastics.

[0057] In another preferred embodiment, the solar shielding coating is applied to the exterior surface III of the inner pane, in which case the outer pane and the thermoplastic interlayer are preferably clear and untinted.

[0058] In a preferred embodiment, the composite pane may have a thermal radiation reflective coating, also known as a low-E coating, on the inner surface (side IV) of the inner pane. Such a low-E coating is particularly advantageous on the inner side of the inner pane, since in this way the heat transfer reducing layer is directly adjacent to the interior of the vehicle. Thus, according to the invention, the composite pane can have a particularly low total transmitted thermal radiation (TTS) of less than 14% (measured according to ISO 13837), while at the same time achieving an optimal aesthetic appearance without undesirable coloring in the reflection of the composite pane. In particular, undesirable red and yellow reflections or haze of the composite pane can be avoided.

[0059] Such coatings are known, for example, from WO 2013 / 131667. The thermal radiation reflecting coating may also be called thermal protection coating, low emissivity coating, emissivity reducing coating, low-E coating or low-E layer. It has the function of reflecting thermal radiation, i.e. IR radiation, which has a longer wavelength than the IR component of solar radiation in particular. When the outside temperature is low, the low-E coating reflects the heat to the inside, reducing the cooling inside. When the outside temperature is high, in addition to the solar shading coating, the low-E coating reflects the thermal radiation of the heated composite pane to the outside, reducing the heating inside. In conjunction with the solar shading coating according to the invention, the low-E coating reduces the emission of thermal radiation from the pane particularly effectively in summer and in winter to the external environment.

[0060] According to the invention, the thermal radiation reflective coatings with low emissivity known up to now, for example from WO 2013 / 127563 or WO 2019 / 110172, are suitable for use in composite panes according to the invention. By combining the solar shading coating according to the invention and the low emissivity coating for composite panes, it is possible to achieve a light transmittance (TL) of visible light of 1-12%, preferably 5%-10%, with improved energy values ​​(TTS<14%).

[0061] The thermal radiation reflective coating of the composite pane preferably comprises functional layers containing a transparent conductive oxide (TCO), preferably indium tin oxide (ITO) or tin oxide (SnO2), which are arranged between dielectric layers, in particular ZnO, SnZnO, AlN, TiO 2 , SiO 2 , or Si 3 N 4 The insulating layer may be formed from a dielectric oxide or nitride, such as

[0062] However, the functional layer of the low-E coating can be made of other conductive oxides, such as fluorine-doped tin oxide (SnO- 2 :F), antimony-doped tin oxide (SnO 2 :Sb), mixed indium zinc oxide (IZO), gallium- or aluminum-doped zinc oxide, niobium-doped titanium oxide, cadmium stannate, and / or zinc stannate, etc. Thus, particularly good results are achieved with regard to the emissivity and bendability of the coating.

[0063] In one embodiment of the present invention, the low-E coating has an emissivity of at most 50%, preferably at most 30%. In other words, the inner emissivity of the composite pane according to the invention is preferably less than or equal to 50%, particularly preferably between 10% and 50%, most particularly preferably between 20% and 35%, for example also preferably less than or equal to 30%. "Inner emissivity" refers to a measure of how much thermal radiation a pane provided with a low-E coating emits inwards, for example into the interior of a building or into the interior of a vehicle, in the installed position, compared to an ideal heat sink (black body). In the context of the present invention, "emissivity" means the normal emissivity at 283 K according to standard EN12898.

[0064] According to the invention, the composite glass pane has an external energy reflection RE>36%, preferably RE>39%. The calculation of the energy value RE is carried out according to the ISO 9050 standard.

[0065] In one embodiment of the composite glass pane according to the invention, when using a standardized A emitter at an incidence angle of 2°, RL ext External reflectance (visible external reflectance RL) of >8%, preferably 10% to 22% ext ) Optical value RL ext The calculation is carried out according to the EN410 standard with illuminant A. Here, the external reflectance represents the reflected portion of the incident visible radiation from the external environment.

[0066] The invention further relates to a method for producing a composite pane according to the invention having a solar shading coating, said method comprising the following steps: a) applying a solar shading coating to the inner surface of the outer pane (II) or to the outer surface of the inner pane (III) or incorporating a solar shading coating into the thermoplastic interlayer; b) producing a stack of layers including at least an outer pane, a thermoplastic intermediate layer, and an inner pane, in that order; and c) bonding the stack of layers including at least an outer pane, a thermoplastic intermediate layer, and an inner pane to form a composite pane.

[0067] In a preferred embodiment of this method, the application of a thermal protective coating on the inner surface (IV) of the inner pane is provided as a further step.

[0068] The solar blocking coating may be applied before, after, or simultaneously with the application of the thermal radiation reflective coating. The outer and inner panes are bonded to form composite glass, preferably after both the solar blocking coating and the thermal protection coating have been applied.

[0069] Both the solar shading coating and the thermal protection coating are able to withstand high thermal loads and therefore also temperature treatment or bending of the pane, typically at temperatures above 600° C., without damage.

[0070] The individual layers of the solar shielding coating and the thermal radiation reflecting coating can be deposited by methods known per se, preferably by magnetron-enhanced cathodic sputtering, and can be built up in suitable layer thicknesses and layer sequences. Cathodic sputtering can be carried out in a protective gas atmosphere, for example in an argon protective gas atmosphere, or in a reactive gas atmosphere, for example with the addition of oxygen or nitrogen. However, the individual layers can also be applied by other suitable methods known to the person skilled in the art, for example by vapor deposition or chemical vapor deposition.

[0071] The thermoplastic interlayer may be provided in the form of a thermoplastic film. However, the thermoplastic interlayer may also be provided in the form of a plurality of films, e.g., two or more thermoplastic films, optionally with an additional carrier film. Application of the solar shading coating onto the thermoplastic interlayer only involves application of the solar shading coating to one of the films, e.g., to the carrier film. When joining the panes to form the composite glass, the carrier film with the solar shading coating disposed thereon is preferably disposed between the two thermoplastic films, with the surface of the solar shading coating facing the outer pane.

[0072] The bonding of the outer and inner panes via the thermoplastic interlayer to form a composite pane is preferably carried out by lamination under the action of heat, vacuum and / or pressure. Methods known per se for manufacturing composite panes may be used. During the lamination process, a heated, flowable thermoplastic material flows around the solar protection coating, establishing a stable bond and encapsulating the latter in the interlayer, protecting it from damage and environmental influences.

[0073] For example, the so-called autoclave process can be carried out at high pressures of about 10 bar to 15 bar and at temperatures of 130° C. to 145° C. for about 2 hours. The vacuum bag or vacuum ring process, known per se, operates, for example, at about 200 mbar and 80° C. to 110° C. The outer pane, the thermoplastic intermediate layer and the inner pane may also be pressed between at least one pair of rollers in a calender, thereby forming the pane. Systems of this type are known for the manufacture of panes and usually have at least one heating tunnel upstream of the pressing unit. The temperature during the pressing operation is, for example, in the range of 40° C. to 150° C. The combination of calendering and autoclave processes has proven to be particularly effective in practice. Alternatively, vacuum laminators can also be used. These consist of one or more heatable and evacuable chambers in which the panes are laminated, for example, within about 60 minutes, at reduced pressures of 0.01 mbar to 800 mbar and at temperatures of 80° C. to 170° C.

[0074] The invention further comprises the use of the composite panes according to the invention with a solar shading coating and optionally a low-E coating in land, air or water transport vehicles, in particular in motor vehicles, e.g. as windscreens, rear windows, side windows and / or roof panels, and as functional individual components, and in buildings.

[0075] All standards mentioned refer to the versions in effect on the filing date.

[0076] The various embodiments of the invention may be implemented individually or in any combination. In particular, the features described above and below may be used not only in the combinations shown, but also in other combinations or alone, without departing from the scope of the invention, unless the exemplary embodiments and / or their features are expressly mentioned only as alternatives or are mutually exclusive.

[0077] The present invention will be described in more detail below with reference to the drawings. It should be noted that various aspects are described and each can be used individually or in combination. In other words, any aspect can be used with various embodiments of the present invention unless expressly presented as a pure alternative.

[0078] The drawings are simplified schematic views and are not to scale. The drawings are not intended to limit the invention. [Brief description of the drawings]

[0079] [Figure 1] FIG. 1 is a cross-sectional view of a first embodiment of a composite pane according to the invention, comprising a solar shielding layer and a thermal radiation reflective layer;

[0080] [Diagram 2] FIG. 2 is a cross-sectional view of another embodiment of a composite pane according to the present invention having a solar shielding layer and a thermal radiation reflective layer;

[0081] [Diagram 3] FIG. 2 is a cross-sectional view of another embodiment of a composite pane according to the present invention having a solar shielding layer and a thermal radiation reflective layer;

[0082] [Figure 4] 1 is a schematic diagram of a structure of a solar shielding layer according to the present invention applied to the outer pane of a composite pane; and

[0083] [Diagram 5] 2 is a flow chart of an embodiment of a method according to the present invention;

[0084] Figure 1 shows a cross-sectional view of an embodiment of a composite pane 100 according to the present invention, having a solar radiation shielding coating 4 and a low-E coating 5. The composite pane 100 includes an outer pane 1 and an inner pane 2 bonded to each other via a thermoplastic interlayer 3. The composite pane 100 can be provided, for example, as a roof panel of a passenger vehicle, with the outer pane 1 facing the external environment and the inner pane 2 facing the interior of the vehicle. The outer pane 1 has an outer side surface (I) and an inner side surface (II). The inner pane 2 has an outer side surface (III) and an inner side surface (IV). The outer side surfaces (I) and (III) face the external environment; the inner side surfaces (II) and (IV) face the interior of the vehicle. The inner side surface (II) of the outer pane 1 and the outer side surface (III) of the inner pane 2 face each other. In this embodiment, the solar radiation shielding coating 4 according to the present invention is disposed on the inner side surface (II) of the outer pane 1. The solar radiation shielding coating 4 preferably extends over the entire inner side surface (II) except for a region without a peripheral frame-shaped coating, for example, a region without a peripheral frame-shaped coating having a width of 8 mm. The region without the coating can then be hermetically sealed by bonding to the thermoplastic interlayer 3. Thus, the solar radiation shielding coating 4 is advantageously protected from damage and corrosion. According to the present invention, the solar radiation shielding coating 4 includes at least three functional silver layers, each having a layer thickness between 5 nm and 20 nm, and each functional silver layer is disposed between dielectric modules, for example, layers of silicon nitride. The silver layers (Ag1, Ag2, Ag3) of the solar radiation shielding coating according to the present invention have a geometric layer thickness of 0.4 < Ag1 / Ag3 < 1.7 with respect to each other, and Ag2 or Ag3 is the thickest silver layer, and the dielectric modules (M1, M2, M3, M4) have an optical layer thickness of M2 / M1 ≧ 1.9, M2 / M3 ≧ 0.8, and M2 / M4 ≧ 1.6 with respect to each other. The structure of the solar radiation shielding coating 4 according to the present invention will be described in more detail below using FIG. 4 and the examples and comparative examples described therein. The solar radiation shielding coating 4 reduces the heating of the interior of the vehicle and the inner pane 2 by reflection of infrared radiation. According to the present invention, an energy reflection RE > 36%, preferably > 39% can be achieved.In addition to a good improvement in thermal comfort compared to conventional systems, the solar shading coating 4 according to the invention also simultaneously provides good optical and aesthetic properties of the composite pane 100. A thermal protection coating 5 is optionally arranged on the inner surface (IV) of the inner pane 2. In this preferred embodiment, the composite pane may not only have a good energy reflection RE>40% but also a low total transmitted thermal emissivity, in particular TTS<14%. On the one hand, the thermal protection coating 5 reduces the emission of thermal radiation through the composite pane 100 into the interior of the vehicle, in particular when the outside temperature is high. On the other hand, the thermal protection coating 5 may reduce the emission of thermal radiation from the interior of the vehicle when the outside temperature is low. Furthermore, the thermal protection coating 5 may reduce the transmission of visible light into the interior of the vehicle. These are the main advantages of the composite pane according to the invention, since the interior environment of the vehicle is significantly improved and the need for the use of air conditioning systems is reduced. From the point of view of energy properties, it is preferred according to the invention to apply the solar shading coating 4 on the transparent, untinted glass pane (the inner surface II of the outer pane 1) in order in particular to achieve an energy reflection RE>36 and the lowest possible TTS value of the resulting composite pane 100. On the other hand, optionally, it may be useful to apply the solar shading coating 4 on the tinted glass pane (the outer pane 1) in order to neutralize or improve the appearance of the composite pane 100. Such a configuration of the composite pane according to the invention, with a transparent, untinted outer pane, a tinted thermoplastic intermediate layer and a tinted inner pane, is in particular suitable as a roof panel of a vehicle.

[0085] FIG. 2 shows a cross-sectional view of another embodiment of a composite pane 100 according to the invention, with a solar-shading coating and a thermal protection coating 4, 5. In contrast to FIG. 1, the solar-shading coating 4 is not arranged on the inner surface (II) of the outer pane 1, but on the carrier film 6 in the intermediate layer 3. The solar-shading coating 4 can be arranged optionally on the surface of the carrier film facing the inner pane 2 or the outer pane 1, in each case according to the layer thickness ratio according to the invention. The carrier film 6 preferably comprises or is made of polyethylene terephthalate (PET) and has a thickness of, for example, 50 μm. The solar-shading layer 4 according to the invention comprises a layer structure, which is explained in more detail with respect to FIG. 4. The carrier film 6 with the solar-shading coating 4 is arranged between a first thermoplastic film 3a and a second thermoplastic film 3b. In the resulting composite pane, the thermoplastic films 3a and 3b and the carrier film 6 form a thermoplastic intermediate layer 3. The thermoplastic films 3a and 3b preferably contain or are made of PVB and have a layer thickness of, for example, 0.38 mm. The carrier film 6 is somewhat smaller than the outer pane 1, the inner pane 2 and the thermoplastic films 3a and 3b. The carrier film 6 is arranged in the composite such that it does not extend to the lateral edges of the composite glass. As a result, the carrier film 6 is peripherally surrounded, for example with a width of about 8 mm, by the thermoplastic films 3a and 3b in the edge region of the composite pane. The solar shading coating 4 on the carrier film 6 is thus advantageously protected against damage, in particular against corrosion. The heat protection coating 5 on the inner surface (IV) of the inner pane 2 is designed as in FIG. 1.

[0086] FIG. 3 shows a cross-sectional view of another embodiment of the composite pane 100 according to the invention, having a solar radiation shielding coating and a thermal protection coating 5, 4. In contrast to FIG. 1, the solar radiation shielding coating 4 is arranged on the outer side surface (III) of the inner pane 2, rather than on the inner side surface (II) of the outer pane 1. The peripheral region of the outer side surface (III) is not provided with the solar radiation shielding coating 4. Also in this embodiment, the solar radiation shielding coating 4 is advantageously protected from damage and corrosion. Otherwise, this embodiment corresponds to the design shown in FIG. 1.

[0087] FIG. 4 shows a schematic structure of the solar radiation shielding layer 4 according to the invention. In the illustrated embodiment, the solar radiation shielding coating 4 is applied on the inner surface II of the outer pane 1 as a substrate. The illustrated solar radiation shielding coating 4 includes three transparent functional silver layers Ag1, Ag2, and Ag3, which are particularly infrared reflecting layers. According to the invention, these functional silver layers have a certain thickness relative to each other; specifically, according to the invention, they are made to have the following with respect to the relative geometric layer thickness: 0.4 < Ag1 / Ag3 < 1.7 and the thickest silver layer being Ag3 or Ag2. In other words, the layer thickness of the first silver layer Ag1, which is arranged closest to the outer pane 1, is thinner than the second silver layer Ag2 or the third silver layer Ag3 that follows Ag1 in the layer arrangement. The silver layers can be deposited, for example, by cathode sputtering in an argon atmosphere.

[0088] The dielectric modules M1, M2, M3 and M4 comprising dielectric layers are arranged above, below and between the silver layers Ag1, Ag2 and Ag3, respectively. According to the invention, these dielectric modules (M1, M2, M3, M4) have optical layer thicknesses M2 / M1≧1.9, M2 / M3≧0.8 and M2 / M4≧1.6 relative to one another. Thus, the dielectric module M1 is arranged directly on the inner side II of the outer pane 1, below the first silver layer Ag1; the second dielectric module M2 is arranged above the first silver layer Ag1. The first dielectric module M1 can be structured, for example, starting from the outer pane 1, as a layer sequence of silicon nitride, ZnSnOx and ZnO layers. The silicon nitride layer can be deposited from silicon nitride in a nitrogen-containing atmosphere; the zinc oxide layer can be deposited from zinc oxide in an oxygen-containing atmosphere.

[0089] The solar shielding coating 4 comprises at least one blocking layer; particularly preferably, each functional silver layer Ag1, Ag2, Ag3 is located in direct contact with at least one blocking layer B1, B2 and B3, as shown. According to the invention, the blocking layers preferably comprise or are made of at least nickel, chromium or alloys thereof and / or titanium chromium. The blocking layer B (B1, B2, B3) is preferably arranged between the at least one functional silver layer and the at least one dielectric layer. The blocking layer B protects the functional layers during heating, in particular during the manufacture of the composite pane according to the invention.

[0090] The invention will now be described with reference to the following inventive and non-inventive comparative examples.

[0091] Working Example

[0092] All optical, aesthetic and energy properties of the composite panes according to the examples and comparative examples were measured in the laminated state. In the examples and comparative examples, a solar shading coating 4 was applied to the inner face II of a transparent outer pane 1 (example Planiclear) according to FIG. 4 and laminated with a thermoplastic intermediate layer 3 and an inner pane 2 according to the structure of FIG. 1. In the intermediate layer, a tinted PVB film was used. A low-E coating was applied to the inner face IV of the inner pane 2, which was tinted with a dark color (example VG10). The low-E coating had an emissivity of 30%. The low-E coating was applied to a dielectric layer (Si 3 N 4 , SiO x The examples and comparative examples have the same basic structure described, but differ in the solar shielding coating used.

[0093] Examples 1-10 according to the invention and a comparative example not according to the invention were manufactured as composite panes (vehicle windshields) having the indicated solar shielding coatings.

[0094] For each example and comparative example, the stack structure (layers and layer thicknesses) of the solar shielding coating and the optical properties of the coating in the finished composite pane are given.

[0095] The layer sequences and layer thicknesses of the solar shading coatings according to Examples 1 to 10 according to the invention are shown in Table 1a. For comparison, Comparative Examples 1 to 4, which are not according to the invention, are listed in Table 1b. The relative layer thicknesses of the silver layers and the dielectric modules as well as the values ​​of the optical and energy properties are reported in Table 2a for Examples 1 to 10 according to the invention and in Table 2b for Comparative Examples 1 to 4, which are not according to the invention. All layer thicknesses of the silver layers and the layers of the modules are shown as geometric layer thicknesses. The relative layer thicknesses of the silver layers, shown as thickness ratios Ag2 / Ag1, Ag2 / Ag3 and Ag1 / Ag3, refer to the geometric layer thicknesses. For the relative layer thicknesses of the dielectric modules, shown as thickness ratios M2 / M1, M2 / M3 and M2 / M4, the optical thicknesses were used.

[0096] Abbreviation RE Energy Reflection [%] TL Visible light transmittance [%] TTS Total transmitted thermal radiation [%] TE Total transmitted energy [%] RL 8° Visible reflection at 8° viewing angle [%] a * , b * Color coordinates in the CIE color space (International Commission on Illumination), measured in reflection at angles of 60° and 8° respectively Δa * , Δb * The difference in color coordinates when measured in reflection at 60° and at 8° Color R * The color impression of the external reflected color in each case, as perceived by an observer of the composite pane, at 60° and at 8° reflection

[0097] Light transmittance (TL) and reflectance (RL) values ​​are based on illuminant A, i.e., the visible portion of sunlight at wavelengths from 380 nm to 780 nm.

[0098] [Table 1]

[0099] [Table 2]

[0100] [Table 3]

[0101] [Table 4]

[0102] According to the present invention, there is provided a composite pane having a solar radiation shielding coating configured according to the present invention, which is well improved and further optimized with respect to the energy characteristics, thermal and visual comfort, and at the same time with respect to the aesthetic appearance, compared to known composite panes having a solar radiation shielding coating. An energy reflection of RE>41%, preferably RE>39% is achieved. When using the solar radiation shielding coating according to the present invention, a composite pane can be provided in combination with a heat radiation reflecting coating, and the pane can further have a particularly low total transmitted heat radiation (TTS) of less than 14%. On the other hand, at the same time, in the reflection of the composite pane, an optimal aesthetic appearance without an undesirable color tone is achieved. In particular, the undesirable red and yellow reflections or haze of the composite pane can be avoided. According to the present invention, a substantially constant desirable color reflection of the composite pane can be obtained regardless of the viewing angle.

[0103] Examples 1 to 5 according to the present invention have silver layers Ag1, Ag2, and Ag3 with relative geometric layer thicknesses of 0.4 < Ag1 / Ag3 < 0.9 and 0.5 < Ag2 / Ag3 < 1.0, where Ag3 is the thickest silver layer, and the dielectric modules (M1, M2, M3, M4) have optical layer thicknesses such that M2 / M1 ≧ 1.9, M2 / M3 ≧ 0.8, and M2 / M4 ≧ 1.6 with respect to each other. Examples 1 to 5 improved the energy reflection.

[0104] Regarding Examples 6 to 10 according to the present invention, for the silver layers Ag1, Ag2, and Ag3, the relative geometric layer thickness is 0.6 < Ag1 / Ag3 < 1.7, where Ag2 is the thickest silver layer, and the dielectric modules (M1, M2, M3, M4) have relative optical layer thicknesses of M2 / M1 ≧ 2, M2 / M3 > 1, and M2 / M4 ≧ 2. These composite panes are particularly advantageous in that the angular-dependent color deviation Δa in reflection is minimized.

[0105] FIG. 5 shows an exemplary embodiment of the method according to the present invention with reference to a flowchart including the following steps. I. Providing an outer pane 1, an inner pane 2, and at least one thermoplastic film (to form a thermoplastic intermediate layer 3); II. applying a solar protection coating 4 according to the invention to the inner surface II of the outer pane 1 or to the outer surface III of the inner pane 2, for example by cathodic sputtering; III optionally applying a thermal protective coating 5 to the inner face IV of the inner pane 2; IV. bonding the inner surface II of the outer pane 1 and the outer surface III of the inner pane 2 via a thermoplastic intermediate layer 3 to form a composite pane 100;

[0106] In one embodiment, a glass pane is used as the outer pane 1 and as the inner pane 2. In a preferred embodiment of the method, a solar-shading coating 4, having at least three functional silver layers Ag1, Ag2, and Ag3, and at least four dielectric modules M1, M2, M3, and M4, is applied to the inner face II of the outer pane 1. It is preferably applied by magnetron-enhanced cathode sputtering. In terms of time, the solar-shading coating 4 can be applied before, after, or simultaneously with the optional application of a thermal radiation-reflecting coating 5 on the inner face IV of the inner pane 2. The joining of the outer pane 1 and the inner pane 2 via the interlayer 3 to form a composite glass is preferably performed after both the solar-shading coating 4 and the optional thermal protection coating have been applied. [Explanation of symbols]

[0107] 1 outer pane, 2 inner pane, 3 thermoplastic intermediate layer, 3a first thermoplastic film, 3b second thermoplastic film, 4 solar shielding coating, 5 heat protection coating, 6 carrier film, I outer surface of 1, II inner surface of 1, III outer surface of 2, IV inner surface of 2, Ag1 first silver layer, Ag2 second silver layer, Ag3 third silver layer, M1 first dielectric module, M2 second dielectric module, M3 third dielectric module, M4 fourth dielectric module, B blocking layer, B1 first blocking layer, B2 second blocking layer, B3 third blocking layer

Claims

1. A composite pane (100) comprising an outer pane (1) having an outer surface (I) and an inner surface (II), an inner pane (2) having an outer surface (III) and an inner surface (IV), and a thermoplastic intermediate layer (3), the thermoplastic intermediate layer (3) connects the inner surface (II) of the outer pane (1) to the outer surface (III) of the inner pane (2); The composite pane (100) has at least one solar shielding coating (4) between the outer pane (1) and the inner pane (2); The solar shielding coating (4) is formed in the following layer sequence starting from the outer pane (1) towards the inner pane (2): a first dielectric module (M1), a first silver layer (Ag1), a second dielectric module (M2), - a second silver layer (Ag2), - a third dielectric module (M3), - a third silver layer (Ag3), - a fourth dielectric module (M4), Including, the silver layers (Ag1, Ag2, Ag3) have a geometric layer thickness relative to one another of 0.4<Ag1 / Ag3<1.7; Ag3 or Ag2 is the thickest silver layer; the dielectric modules (M1, M2, M3, M4) have an optical layer thickness relative to one another of M2 / M1≧1.9, M2 / M3≧0.8, and M2 / M4≧1.6, and all dielectric layers of the dielectric modules (M1, M2, M3, M4) have a refractive index greater than 1.8; Composite pane (100).

2. 2. The composite pane (100) according to claim 1, wherein the silver layers (Ag1, Ag2, Ag3) of the solar shielding coating have, relative to one another, a geometric layer thickness of 0.6<Ag1 / Ag3<1.7; Ag2 being the thickest silver layer; and the dielectric modules (M1, M2, M3, M4) have, relative to one another, an optical layer thickness of M2 / M1≧2, M2 / M3>1, and M2 / M4≧2.

3. 2. The composite pane (100) according to claim 1, wherein the silver layers (Ag1, Ag2, Ag3) of the solar shielding coating have, relative to one another, geometric layer thicknesses of 0.4<Ag1 / Ag3<0.9 and 0.5<Ag2 / Ag3<1.0; Ag3 being the thickest silver layer; and the dielectric modules (M1, M2, M3, M4) have, relative to one another, optical layer thicknesses of M2 / M1≧1.9, M2 / M3≧0.8, and M2 / M4≧1.

6.

4. The composite pane (100) according to any one of claims 1 to 3, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3) and / or the fourth dielectric module (M4) have at least one dielectric layer based on silicon nitride.

5. The composite pane (100) according to any one of claims 1 to 4, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3) and / or the fourth dielectric module (M4) comprise at least one first dielectric layer based on silicon nitride and at least one second dielectric layer based on zinc oxide.

6. 6. The composite pane (100) according to any one of claims 1 to 5, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3) and / or the fourth dielectric module (M4) comprise at least one first dielectric layer based on silicon nitride, at least one second dielectric layer based on zinc oxide and at least one third dielectric layer based on mixed tin-zinc oxide.

7. 7. Composite pane according to any one of the preceding claims, wherein the solar shielding coating (4) comprises at least one metal blocking layer (B1, B2, B3) above and / or below the silver layer (Ag1, Ag2, Ag3), respectively, having a geometric thickness of less than 1 nm.

8. 8. Composite pane according to any one of the preceding claims, wherein the first silver layer (Ag1), the second silver layer (Ag2) and the third silver layer (Ag3) each have a geometric thickness of 5 nm to 25 nm, preferably 8 nm to 20 nm.

9. 9. A composite pane according to any one of claims 1 to 8, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3) and the fourth dielectric module (M4) each have a geometric thickness of 10 nm to 100 nm, preferably 20 nm to 90 nm, particularly preferably 70 nm to 85 nm.

10. A composite pane according to any one of the preceding claims, wherein the solar shielding coating (4) is applied to the inner surface (II) of the outer pane (2).

11. A composite pane according to any one of the preceding claims, wherein a thermal radiation reflective coating (5) is applied to the interior surface (IV) of the inner pane (2).

12. The thermal radiation reflective coating (5) is an indium tin oxide layer (ITO) or a tin oxide layer (SnO ２ 12. The composite pane according to claim 11, comprising a functional layer based on indium tin oxide or tin oxide, the indium tin oxide layer being disposed between two dielectric layers.

13. at least, (a) applying a solar shading coating (4) to the inner surface (II) of the outer pane (1) or to the outer surface (III) of the inner pane (2) or incorporating a solar shading coating (4) in a thermoplastic intermediate layer (3), (b) producing a stack of layers comprising at least said outer pane (1), said thermoplastic intermediate layer (3) and said inner pane (2) in that order; and (c) bonding a stack of layers including at least the outer pane (1), the thermoplastic intermediate layer (3), and the inner pane (2) to form a composite pane (100); The steps include: A method for manufacturing a composite pane (100) according to any one of claims 1 to 12.

14. A method for manufacturing a composite pane (100) according to claim 13, characterized in that a thermal radiation reflective coating (5) is applied to the interior surface (IV) of the inner pane (2).

15. Use of a composite pane (100) according to any one of claims 1 to 12 in a motor vehicle, preferably as a windscreen, rear window, side window and / or roof panel, particularly preferably as a roof panel of a motor vehicle.

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